This disclosure relates to seals and more particularly, to active material based seal assemblies for sealing opposing surfaces.
Current methods and assemblies for sealing opposing surfaces such as doors and trunk lids, for example, include the use of flexible elastic membranes and structures that compress upon pressing contact of the opposing surfaces to form a seal. Typical materials include various forms of elastomers, e.g., foams and solids, that are formed into structures having solid and/or hollow cross sectional structures. The geometries of the cross sections are varied and may range from circular forms to irregular forms having multiple slots, various internal cross section geometries, and extending vanes.
Sealing assemblies are typically utilized for sound, airflow, and/or fluid management. The seals generally are exposed to a variety of conditions. For example, in vehicle applications, door seals generally are exposed to a wide range of temperatures as well as environmental conditions such as rain, snow, sun, humidity conditions, and the like. They must also be resistant to abrasion and repeated cycling. Current materials utilized for automotive seals are passive. That is, other than innate changes in modulus of the seal material due to environmental stimuli, the stiffness and cross sectional geometries of the seal assemblies cannot be remotely changed or controlled.
Another problem with current seals is the tradeoff in seal effectiveness. Increasing the static interface pressure and/or area of the seal can generally increase seal effectiveness. However, in automotive applications, such as vehicle doors, the increased interface pressure and/or area of the seal can result in increased door opening and closing efforts.
Accordingly, it is desirable to have active seal assemblies that can be controlled and remotely changed to alter the seal effectiveness, wherein the active seal assemblies actively change shape, orientation and modulus properties. In this manner, in seal applications such as the vehicle door application noted above, door opening and closing efforts can be minimized yet seal effectiveness can be maximized.